For stator cores for rotating electric machines, various techniques have conventionally been proposed. For example, Japanese Patent Laying-Open No. 2006-352991 (Patent Literature 1) proposes a stator core, wherein strip core raw materials, each having a recess at an end face of one end and a protrusion at an end face of the opposite end, are fitted to achieve coupling when being plastically deformed to form a cylindrical shape, and a constriction is provided at the mouth of the recess or the neck portion of the protrusion to thereby prevent falling-out after fitting.
Japanese Patent Laying-Open No. 2006-340509 (Patent Literature 2) proposes a technique wherein a joint surface between stator core segments represents an approximately trapezoidal uneven shape, and the joint surface area with other stator core segments is increased to reduce magnetic resistance. Japanese Patent Laying-Open No. 2007-129835 (Patent Literature 3) proposes a technique wherein a joint surface between stator core segments represents an uneven shape, and an abutting pressure is made larger at an abutment on the inner circumferential side than at an abutment on the outer circumferential side. Japanese Patent Laying-Open No. 2008-206262 (Patent Literature 4) proposes a technique wherein a joint surface between stator core segments represents a stepped shape, and represents an uneven shape when viewed in plan view.